Three people are dead and dozens injured after a car went into the crowds in the southeastern Austrian city of Graz on Saturday, according to local media report.

The witness of the incident said the car went into the crowds in the city center with a very high speed.

A number of 34 people were injured in the incident, in which six are seriously hurt, and now are still in critical condition. One of the three victims who died is a seven-year-old boy.

The driver of the fatal car is a 26-year-old man who have been arrested by police, and is suspected to have psychosis.

Austrian police found no drug or alcohol in his car, but local media said the driver who has his own family and children was accused of abusing family violence in May.

Local media reported the driver has immigrant background and lives near the city of Graz.

After going on rampage, the 26-year-old man drove his car to the local police station and gave himself up to police.

Witnesses also reported the driver got off his car to attack passerby with his knife.

Austrian official said initial investigations indicated the incident was not terror-related. The local government sent around 60 ambulances to the scene.

Graz is Austria's second largest city, and the capital of Steiermark, a southeastern state of Austria.

The incident happened at around noon local time, when the mayor of Graz was riding a Vespa only meters away from the car as it went down the street.

The city center, where the incident took place, is Graz's main shopping street.